The bird's home turf had been the Lake District's Riggindale Valley, at Haweswater. The high-flying predator had occupied the territory since 2001, according to the RSPB, and he had been alone since 2004, when his mate died.

According to the organization, the eagle was last seen in November 2015. Experts there say it's not unusual for the bird to go unseen in the winter, but his absence from springtime skies is ominous. Normally, they say, this would be the time of year he would be seen building a nest and making displays in his territory to try to attract a mate.

"When the eagle didn't appear last month we thought there was a chance he might be hunting in a nearby valley, but over the past few weeks we've been gradually losing hope," said Lee Schofield, RSPB site manager for the bird's territory, in a statement.

The RSPB doesn't think it's likely golden eagles will settle again in the area anytime soon. There's not enough food or suitable land. But the organization plans to restore the habitat, in hopes of encouraging more small wildlife into the area, which would provide a stable food source for eagles.

Schofield said the missing bird is about 20 years old - getting up there for an eagle - and that it's possible he died of natural causes.

"His disappearance marks the end of an era," Schofield said, "as he has been an iconic part of the Haweswater landscape for the past 15 years. During this time, thousands of visitors have traveled from across the country hoping to catch a glimpse of him at the Riggindale Eagle Viewpoint. With him gone, the Lake District has just got a bit less wild."

Ah, summer -- a time of warmth, sunshine, and artificially circulated air billed by the kilowatt hour. How about a natural breeze made by wings instead? Ones that span more than 10 feet tip-to-tip?
Join us as we survey a collection of birds with just plain amazing wingspans. We'll be sure to let you know when you're looking at the big kahuna -- that is, the largest wingspan among living birds.
For starters, here we see the bearded vulture, tending to youngins. The hulking creature can weigh 15 pounds, with wings that can span 9.3 feet. It enjoys living at high elevations -- cliffs, for example, that might overlook greener vistas where enough prey and predators exist that they can scavenge on the leftovers. There are more than a dozen subspecies, and they have an extensive range -- from southern Europe, to Asia, to Africa.

The California condor has the widest wingspan of any bird in North America, topping out at about 9.8 feet. It weighs an astonishing 26 pounds and, being a vulture, the scavenger dines on a diet heavy on dead animals.
By 1987 it had become extinct, the remaining birds in the wild captured and protected. However, they have since been reintroduced into the wild in parts of Arizona, California and Utah.

You're looking at North America's largest predatory bird, the golden eagle. With a wingspan that can reach about 7.5 feet, the dark-brown raptor can also be found in North Africa, Europe, and Asia.
They love open spaces, anywhere from sea level to more than 2 miles in elevation. They eat the usual poor critters on the ground that can't evade them, such as rabbits, ground squirrels, prairie dogs, and marmots. In the wild, they can live to some 30 years old.
If you click this link below, you'll get an even better idea of a golden eagle's size, as it takes down an atypical form of prey: an unlucky young deer.

The great white pelican puts tons of span in its wings, with a mind-boggling wingspan of about 9.5 feet.
With a penchant for warm and shallow waters, these birds can be found in Europe, Asia and Africa. They eat mostly fish and will fly more than 50 miles in a day while seeking food.

The Andean condor lives in the Andes Mountains and along the Pacific coastline of South America. Its wingspan can reach 10 feet across, and these vultures put their powerful flappers to good use searching for dead deer, cattle or other carrion.

Speaking of vultures, here's another one -- the griffon. Its wings can span a bit more than 9 feet across and it can weigh up to 25 pounds.
True to its vulturesome nature, it also prefers to lead a scavenging lifestyle, making its humble living in southern Europe, Asia and Africa.

Meet the marabou stork. Its top recorded wingspan is 10.5 feet. It lives in sub-Saharan Africa and has been uncharitably compared to an undertaker in appearance, with its heavy black wings, spindly legs and white feathers on its head. It's even known to have a bit of a bad temper.

The whooper swan boasts a wingspan of about 9 feet and can weigh up to 31 pounds. These northern hemisphere birds spend a great deal of time in the water and have a wide breeding range across sub-Arctic Europe and Asia. Strong fliers, they'll migrate hundreds to thousands of miles.
And, on a romantic note, their pairs mate for life.

Finally! The bird you've all been waiting for. Here's the longest wingspan of any living bird, and it belongs to the wandering albatross. You can see why one is inherently uncomfortable to have around one's neck.
How wide a wingspan, you ask? About 11.6 feet at its top length! Even greater spans have been alleged, but not verified. Its mean wingspan among the species, meanwhile, hits 10.2 feet. The seabirds dine at night on fish, crustaceans, cephalopods, and whatever other animal remains they can find just floating in the water for the taking. They'll follow ships looking for just such fare.
Adults typically weight about 25 pounds and they can live up to about 50 years.